Hitherto, an optical film for liquid crystal display (LCD), which is formed by forming various pressure-sensitive adhesive layers such as an acrylic pressure-sensitive adhesive layer on an optical base film for attaching to a liquid crystal cell, such as a polarizing film, a retardation film, or an elliptically polarizing film formed by laminating these films, has been proposed. Such an optical film is formed by previously forming a pressure-sensitive adhesive layer for attaching to a liquid crystal cell on an optical base film for the purpose of improving the efficiency of LCD assembling and preventing the occurrence of dispersion of quality.
In the optical films for LCD described above, with the increase of the wide use of LCD in various fields as electronic watches, televisions, equipments for loading in cars, etc., and in particular, with the recent increase of the performance and the size of LCD, it has been required that the optical films have the characteristics such as the improved heat resistance and moisture resistance in the state of being mounted on LCD, that is, the characteristics of not causing foaming and peeling even in using in a high-temperature and high-humidity atmosphere such as a heating and moistening treatment, etc.
However, conventional optical films have problems in that these films are poor in heat resistance and moisture resistance, and when they are used in a high-temperature and high-humidity atmosphere, foaming and peeling occur at, for example, the interface between a liquid crystal cell and the optical film to decrease a visual recognition property of the display.